public static Matrix Invert(Matrix input)
{
return(new Matrix(Matrix4x4.Invert(input)));
}
private void UpdateMatrices()
{
if (m_dirty)
{
m_viewMatrix = XnaMatrix.CreateLookAt(Position, LookAt, Up);
m_projectionMatrix = IsPerspective
? XnaMatrix.CreatePerspective(ViewportWidth, ViewportHeight, NearPlane, FarPlane)
: XnaMatrix.CreateOrthographic(ViewportWidth, ViewportHeight, NearPlane, FarPlane);
m_toProjection = PostWorldMatrix * m_viewMatrix * m_projectionMatrix;
m_invToProjection = m_toProjection.Invert();
var forward = XnaVector.Normalize(LookAt - Position);
var position = Position + NearPlane * 1.01f * forward;
var xAxis = XnaVector.Cross(forward, Up);
var yAxis = XnaVector.Normalize(XnaVector.Cross(xAxis, forward));
var mat = XnaMatrix.CreateWorld(position, forward, yAxis);
var vpWidth = Math.Abs(ViewportWidth);
var vpHeight = Math.Abs(ViewportHeight);
m_alignToNearPlane = PostWorldMatrix * XnaMatrix.CreateScale(vpWidth * 0.5f, vpHeight * 0.5f, 1) * mat * PostWorldMatrix.Invert();
m_dirty = false;
}
}